TWI670352B - Long strip of adhesive film - Google Patents

Abstract

An object of the present invention is to provide a long-shaped adhesive film which can be used as a surface protective film or a mask when it is suitable for processing a predetermined portion of a long film.

In the solution, the long adhesive film of the present invention has a long resin film and an adhesive layer provided on one surface of the resin film, and has a through hole penetrating through the resin film and the adhesive layer as a whole. They are arranged at predetermined intervals along the strip direction and/or the width direction.

Description

Long strip of adhesive film Field of invention

The present invention relates to a long strip of adhesive film. More specifically, the present invention relates to an elongated adhesive film having through holes arranged in a predetermined pattern.

Background of the invention

Some electronic components such as cameras are mounted on video display devices such as mobile phones and notebook personal computers (PCs). Various discussions have been made for the purpose of improving the camera performance of such an image display device (for example, Patent Documents 1 to 7). However, with the rapid spread of smart phones and touch-sensitive information processing devices, everyone expects to further improve camera performance. Moreover, in order to respond to the diversification and high functionality of the image display device, a polarizing plate having partial polarization performance is required. In order to achieve such demands both industrially and commercially, it is expected to manufacture image display devices and/or their components at a licensed cost, but to establish their technology, there are still various issues to be reviewed.

Prior technical literature Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-81315

Patent Document 2: Japanese Laid-Open Patent Publication No. 2007-241314

Patent Document 3: US Patent Application Publication No. 2004/0212555

Patent Document 4: Korean Laid-Open Patent Publication No. 10-2012-0118205

Patent Document 5: Korean Patent No. 10-1293210

Patent Document 6: Japanese Laid-Open Patent Publication No. 2012-137738

Patent Document 7: US Patent Application Publication No. 2014/0118826

Summary of invention

The present invention has been made to solve the above-mentioned problems, and a main object thereof is to provide a long-shaped adhesive film which can be used as a surface protective film or a mask when it is suitable for processing a predetermined portion of a long film.

The adhesive film of the present invention has a long resin film and an adhesive layer provided on one surface of the resin film, and has a through hole penetrating through the resin film and the adhesive layer as a whole, and the through hole is along a long direction and/or Or the width direction is configured at predetermined intervals.

In one embodiment, the through holes are arranged at predetermined intervals along the longitudinal direction.

In one embodiment, the through holes are arranged at substantially equal intervals along at least the longitudinal direction.

In one embodiment, the through holes are arranged at substantially equal intervals along the longitudinal direction and the width direction.

In one embodiment, the linear direction connecting the adjacent through holes is in the range of ±10° with respect to the longitudinal direction and/or the width direction.

In one embodiment, the through holes are arranged in a dot shape.

In one embodiment, the through hole has a shape of a plan view that is slightly rounded or slightly rectangular.

In one embodiment, the adhesive film further has a long spacer that is peelably temporarily bonded to the adhesive layer.

In one embodiment, the through hole penetrates the spacer, the resin film, and the adhesive layer as a whole.

In one embodiment, the adhesive film is wound into a roll shape.

In one embodiment, the adhesive film is bonded to the elongated film so as to be aligned with each other in the longitudinal direction, and is used to selectively perform a treatment on a portion of the film corresponding to the through hole.

In one embodiment, the adhesive film can be used to manufacture a long strip-shaped polarizer having a non-polarized portion.

In one embodiment, the periphery of the through hole on the side of the adhesive layer is formed into a circular arc surface.

According to the present invention, it is possible to provide an adhesive film which is elongated and has a through hole which is disposed at a predetermined interval (i.e., in a predetermined pattern) in the longitudinal direction and/or the width direction. Such an adhesive film can be used as a surface protective film or a mask, for example, when it is suitable for selectively treating a predetermined portion of a film (representatively, a long film). By using such an adhesive film, Since the continuous processing of the roll conveyance can be performed, the processing efficiency of various selective treatments can be made very high. Further, by using such an adhesive film, the portion to be selectively treated can be precisely controlled in the entire elongated film, and therefore, when the final product of a predetermined size is cut out from the elongated film, each of the final products can be remarkably suppressed The quality of a final product is mixed.

10‧‧‧Resin film

20‧‧‧Adhesive layer

22‧‧‧Parts

30‧‧‧through holes

100‧‧‧Adhesive film

200‧‧‧Polar plate

θ _L ‧‧‧predetermined angle

θ _W ‧‧‧predetermined angle

Fig. 1 is a schematic perspective view of an adhesive film according to an embodiment of the present invention.

2A is a schematic cross-sectional view of the adhesive film of FIG. 1.

Fig. 2B is a schematic cross-sectional view showing an adhesive film according to another embodiment of the present invention.

Fig. 3A is a schematic plan view showing an example of an arrangement pattern of through holes in an adhesive film according to an embodiment of the present invention.

Fig. 3B is a schematic plan view showing another example of the arrangement pattern of the through holes in the adhesive film according to the embodiment of the present invention.

Fig. 3C is a schematic plan view showing still another example of the arrangement pattern of the through holes in the adhesive film according to the embodiment of the present invention.

Fig. 4 is a schematic perspective view showing the bonding of an adhesive film and a polarizing member in a method of manufacturing a polarizing member using an adhesive film according to an embodiment of the present invention.

Fig. 5 is a schematic view showing the formation of a non-polarizing portion in a method of manufacturing a polarizing member using an adhesive film according to an embodiment of the present invention.

Fig. 6 is an observation photograph of a state in which the adhesive film of the embodiment is attached to a polarizing member.

Form for implementing the invention

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited by the embodiments.

A. Adhesive film

A-1. The overall composition of the adhesive film

Fig. 1 is a schematic perspective view of an adhesive film according to an embodiment of the present invention, and Fig. 2A is a cross-sectional view thereof. The adhesive film 100 is elongated, and the upper system is wound into a roll as shown in FIG. In the present specification, the "long strip shape" means an elongated shape having a sufficiently long length with respect to the width, and includes, for example, an elongated shape having a length of 10 times or more and preferably 20 times or more with respect to the width. The adhesive film 100 has a long resin film 10 and an adhesive layer 20 provided on one surface of the resin film 10. The adhesive film 100 has a through hole 30 that penetrates through the resin film 10 and the adhesive layer 20 as a whole, and the through holes 30 are arranged at predetermined intervals (that is, in a predetermined pattern) in the longitudinal direction and/or the width direction. The arrangement pattern of the through holes 30 can be appropriately set in accordance with the purpose. For example, the through hole 30 may be disposed at substantially equal intervals in both the longitudinal direction and the width direction as shown in FIG. 1 . In addition, "there are substantially equal intervals in both the strip direction and the width direction" means that the intervals in the strip direction are equal intervals and the intervals in the width direction are equal intervals, and the interval between the strip directions and the width direction need not be equal. For example, when the interval between the strip directions is L1 and the interval between the width directions is L2, L1=L2 or L1≠L2 may be used. Alternatively, the through holes 30 may be disposed at substantially equal intervals along the strip direction and at different intervals in the width direction; or may be disposed at different intervals along the strip direction and at substantially equal intervals in the width direction (both Not shown). When the through holes are arranged at different intervals in the longitudinal direction or the width direction, the intervals of the adjacent through holes may be different from each other, or only a part (the interval between the specific adjacent through holes) may be different. Further, a plurality of regions may be formed along the strip direction of the adhesive film 100, and the interval between the through holes 30 in the longitudinal direction and/or the width direction may be set in each region.

Practically, as shown in FIG. 2B, the adhesive layer 20 is temporarily peelably bonded to the elongated spacer 22, and the adhesive layer can be protected until the actual use and roll formation can be performed. At this time, the through hole 30 is integrally penetrated through the spacer 22, the adhesive layer 20, and the resin film 10 as shown in FIG. 2B.

3A is a schematic plan view showing an example of an arrangement pattern of through holes in the adhesive film according to the embodiment of the present invention; FIG. 3B is a schematic plan view showing another example of the arrangement pattern of the through holes; and FIG. 3C is a view showing the arrangement pattern of the through holes. A schematic plan view of an example. In one embodiment, the through hole 30 is arranged such that a straight line connecting adjacent through holes in the longitudinal direction is substantially parallel with respect to the longitudinal direction as shown in FIG. 3A, and adjacent through holes are connected in the width direction. The straight lines are substantially parallel with respect to the width direction. This embodiment corresponds to the through hole arrangement pattern in the adhesive film shown in Fig. 1 (Fig. 3A corresponds to the plan view of Fig. 1). In another embodiment, the through hole 30 is arranged such that a straight line connecting the adjacent through holes in the longitudinal direction is substantially parallel with respect to the longitudinal direction as shown in FIG. 3B, and is connected adjacently in the width direction. The straight line of the hole has a predetermined angle θ _W with respect to the width direction. In still another embodiment, the through hole 30 is arranged such that a straight line connecting the adjacent through holes in the longitudinal direction has a predetermined angle θ _L with respect to the longitudinal direction as shown in FIG. 3C, and the phase is connected in the width direction. The straight line of the adjacent through hole has a predetermined angle θ _W with respect to the width direction. θ _L and/or θ _{W are} desirably greater than 0° and ±10° or less. Here, "±" means that both the clockwise direction and the counterclockwise direction are included with respect to the reference direction (the strip direction or the width direction). The embodiment shown in Figs. 3B and 3C has the advantage that, as will be described later, one of the uses of the adhesive film of the present invention can be used to manufacture a polarizing member having a non-polarizing portion. By using the adhesive film of the present invention, the non-polarized portion can be formed in a desired pattern while the long polarizing member is subjected to roll transport. As a result, the arrangement pattern can be precisely controlled in the entire strip-shaped polarizer to form the non-polarized portion. Here, depending on the image display device, it is sometimes required to arrange the absorption axis of the polarizer to be offset by about 10° with respect to the long side or the short side of the device in order to improve the display characteristics. Since the absorption axis of the polarizer appears along the strip direction or the width direction, the non-polarized portion is formed by using the adhesive film of the pattern shown in FIGS. 3B and 3C, and the entire strip-shaped polarizer can be unified at the time. The positional relationship between the non-polarized portion and the absorption axis is controlled, and a final product having excellent axial accuracy (and thus excellent optical characteristics) can be obtained. Therefore, the absorption axis direction of the single-plate polarizing member which is cut (for example, cut and perforated in the longitudinal direction and/or the width direction) can be precisely controlled to a desired angle, and each of the polarized lights can be remarkably suppressed The direction of the absorption axis of the piece is staggered. Needless to say, the arrangement pattern of the through holes is of course not limited by the example of the drawings. For example, the through hole 30 may be configured such that a straight line connecting the adjacent through holes in the longitudinal direction has a predetermined angle θ _L with respect to the longitudinal direction, and a straight line connecting the adjacent through holes in the width direction is substantially opposite to the width direction. The top is parallel. Further, a plurality of regions may be regulated along the strip direction of the adhesive film 100, and θ _L and/or θ _{W may be} set in each region.

The shape of the through hole 30 in plan view can be arbitrarily and suitably shaped depending on the purpose. Specific examples include a circle, an ellipse, a square, a rectangle, and a diamond.

The through hole 30 can be formed, for example, by cutting or removing a predetermined portion of the adhesive film (for example, laser ablation or chemical dissolution). The cutting method includes, for example, a method of mechanically cutting using a cutting blade (punching type) such as a Thomson blade or a sharp edge, a water jet, and the like, and a method of cutting by irradiating with laser light.

Cutting by the cutting edge can be carried out by any suitable and suitable pattern. For example, it is possible to use a punching device in which a plurality of cutting edges are arranged in a predetermined pattern, and the cutting blade can be moved by using an apparatus such as an XY plotter. In this way, the cutting blade can be moved and cut so as to correspond to the predetermined position of the adhesive film, so that the through hole can be formed with high precision at a desired position of the adhesive film. In one embodiment, the cutting of the cutting edge can be performed in conjunction with the conveyance in the case where the long adhesive film is conveyed by the roller. In more detail, it is possible to appropriately adjust the moving speed of the cutting timing and/or the cutting edge in consideration of the conveying speed of the adhesive film, thereby forming a through hole at a desired position of the adhesive film. Moreover, the above-mentioned punching device may be in a reciprocating mode (translation) or a rotating mode (swinging).

Any and suitable laser can be used as long as the adhesive film can be cut off. It is desirable to use a laser that emits light in a wavelength range of 193 nm to 10.6 μm . Specific examples include gas lasers such as CO ₂ lasers and excimer lasers; solid lasers such as YAG lasers; and semiconductor lasers. Ideally CO ₂ lasers can be used. At the time of cutting, the irradiation conditions of the laser light can be set to an arbitrary and appropriate condition, for example, depending on the laser used. When a CO ₂ laser is used, the output condition is, for example, 0.1 W to 250 W.

The above laser ablation can be performed by any suitable and suitable pattern. Lasers for use in laser ablation may employ any and suitable lasers. As a specific example, the same laser as the above-described laser used for cutting can be mentioned. In the case of laser ablation, the irradiation conditions (output conditions, moving speed, and number of times) of the laser light may correspond to the formation material of the adhesive film (substantially the resin film and the adhesive layer), the thickness of the adhesive film, the plan view shape of the through hole, and the through hole. Arbitrary and suitable conditions are employed for the area and the like.

When cutting the adhesive film, the abutting material should be abutted on one side of the adhesive film. Specifically, the abutting material abuts against the surface of the adhesive film on the terminal side in the cutting direction. By using the abutting material, the piercing waste can be simultaneously removed when the abutting material is peeled off from the adhesive film after cutting. Specifically, the abutting material can be peeled off from the adhesive film in a state where the perforated waste adheres to the abutting material. As a result, productivity can be improved. Further, by using the abutting material, deformation of the adhesive film due to cutting can be suppressed. For example, when the cutting is performed by the cutting blade, deformation of the adhesive layer can be particularly suppressed.

In a preferred embodiment, the through hole is formed by cutting a portion of the adhesive film from the surface of the adhesive film. According to this aspect, the through hole which penetrates the resin film and the adhesive layer as a whole (and the spacer is also provided at the time of installation) can be formed favorably. Further, when the abutting material is peeled off from the adhesive film, the perforated waste can be satisfactorily removed.

It is desirable to use a polymer film as the above-mentioned abutting material. For the polymer film, the same film as the above resin film can be used. Further, a film such as a polyolefin (e.g., polyethylene) film (e.g., having a low modulus of elasticity) may also be used. In one embodiment, the polymer film is preferably a film having a high hardness (for example, elastic modulus). This is because the deformation of the cut adhesive film can be well suppressed. The thickness of the polymer film is preferably 20 μm to 100 μm .

Ideally, the abutting material can be adhered to the adhesive film by an adhesive. By attaching the abutting material to the adhesive film, it is possible to prevent the displacement of the abutting material from being abnormal during cutting. Further, when the abutting material is peeled off from the adhesive film, the perforated waste can be well removed. As the adhesive for bonding the abutting material, any adhesive agent can be used as long as it has an adhesive force capable of peeling the contact material from the adhesive film after cutting. In one embodiment, the adhesive layer is formed in advance on the abutting material. The thickness of the adhesive layer formed on the abutting material is preferably from 1 μm to 50 μm .

In one embodiment, the shape of the abutting material corresponds to the shape of the adhesive film. For example, for a long adhesive film, a long strip of abutting material can be used. If it is such a shape, the piercing waste can be well removed when the abutting material is peeled off from the adhesive film. Moreover, the perforated waste can be continuously removed, and the productivity is excellently improved.

When the through hole is formed, it is preferably cut from the side of the spacer of the adhesive film. By cutting from the separator side, the influence on the adhesion of the adhesive film obtained by cutting can be suppressed. Specifically, when the cutting blade is cut, the adhesive layer of the adhesive film may be deformed following the cutting edge. When the resin film is cut from the side of the resin film, the adhesive layer may swell on the side of the adhesive surface of the obtained adhesive film to form a bulging portion at the periphery of the through hole. As a result, when the obtained adhesive film is attached to the object to be attached, air bubbles may be generated around the through hole. On the other hand, if it is cut from the side of the spacer, the adhesive layer may be deformed after chasing the cutting edge. However, since the peripheral edge of the adhesive surface of the through-hole of the obtained adhesive film is in a smooth state (for example, a circular arc surface), even if it is bonded to the object, the generation of bubbles can be prevented. Further, by cutting from the separator side, when the abutting material is used, the perforated scrap can be satisfactorily removed when the abutting material is peeled off from the adhesive film after the cutting. For example, it is possible to prevent the removal of only a part of the perforated waste (represented as a spacer portion).

A-2. Resin film

The resin film 10 can be used as a substrate of the adhesive film 100. The resin film is preferably a film having a high hardness (for example, elastic modulus). This prevents deformation of the through hole at the time of conveyance and/or bonding. The material for forming the resin film is, for example, an ester resin such as a polyethylene terephthalate resin, a cycloolefin resin such as a norbornene resin, an olefin resin such as polypropylene, a polyamide resin, or a polycarbonate system. Resins and copolymer resins of the above. An ester resin (especially a polyethylene terephthalate resin) is preferred. In the case of such a material, the elastic modulus is sufficiently high, and even when tension is applied during transportation and/or bonding, the through hole is not easily deformed.

The thickness of the resin film is represented by 20 μm to 250 μm , preferably 30 μm to 150 μm . If the thickness is this, there is an advantage that deformation of the through hole is less likely to occur even when tension is applied during conveyance and/or bonding.

The elastic modulus of the resin film is desirably 2.2 kN/mm ² to 4.8 kN/mm ² . When the elastic modulus of the resin film is within this range, there is an advantage that deformation of the through hole is less likely to occur even when tension is applied during conveyance and/or bonding. Further, the modulus of elasticity was measured in accordance with JIS K 6781.

The tensile elongation of the resin film is desirably from 90% to 170%. Resin thin If the tensile elongation of the film is within this range, there is an advantage that it is not easily broken during transportation. Further, the tensile elongation was measured in accordance with JIS K 6781.

A-3. Adhesive layer

The adhesive forming the adhesive layer may be any and suitable adhesive. The matrix resin of the adhesive is, for example, a propylene resin, a styrene resin, or a polyoxymethylene resin. From the viewpoints of chemical resistance, adhesion to prevent penetration of the treatment liquid during immersion, and degree of freedom with respect to the object to be conjugated, propylene-based resin is preferred. The crosslinking agent which may be contained in the adhesive is, for example, an isocyanate compound, an epoxy compound, or an anthracycline compound. The adhesive may also contain, for example, a decane coupling agent. The blending formula of the adhesive can be appropriately set according to the purpose.

The thickness of the adhesive layer is preferably from 1 μm to 60 μm , preferably from 3 μm to 30 μm . If the thickness is too thin, the adhesiveness may become insufficient and bubbles may enter the adhesive interface. If the thickness is too thick, it is easy to cause an abnormality such as an overflow of the adhesive.

A-4. Partition

The spacer 22 has a function as a protective adhesive film (adhesive layer) until it is provided as a practical protective material. Further, by using the spacer, the adhesive film can be wound into a roll shape favorably. The separator may be a surface-coated plastic such as a polyethylene terephthalate release agent, a fluorine-based release agent, or a long-chain alkyl acrylate release agent (for example, polyethylene terephthalate). Ester (PET), polyethylene, polypropylene) film, non-woven fabric or paper. The thickness of the spacer can be any and suitable thickness for the purpose. The thickness of the spacer is, for example, 10 μm to 100 μm .

B. Use of adhesive film

The adhesive film of the present invention is suitably used, for example, as a surface protective film or mask when selectively treating a predetermined portion of a film (represented as a long film). Specific examples of the selective treatment include decolorization, coloring, perforation, development, etching, patterning (for example, formation of an active energy ray-curable resin layer), chemical modification, and heat treatment. By using the adhesive film of the present invention, continuous processing at the same time as the roll conveyance can be achieved, so that the processing efficiency of various selective treatments can be greatly improved. Further, by using the adhesive film of the present invention, the portion to be selectively treated can be precisely controlled in the entire elongated film, and therefore, when the final product of a predetermined size is cut out from the long film, the film can be remarkably Suppresses the quality of each final product. In one embodiment, the adhesive film of the present invention can be used to produce a polarizing member (represented as a long strip of polarizing member) having a non-polarizing portion. By using the adhesive film of the present invention for this purpose, it is possible to achieve low cost. High yield. Highly productive manufacturing of polarizers that meet the versatility and high functionality of electronic devices such as image display devices. Hereinafter, the manufacture of the polarizer having the non-polarizing portion will be specifically described with respect to the representative example of the selective processing described above.

C. Manufacture of a polarizer having a non-polarizing portion

C-1. Polarizer

The polarizing member which can form the non-polarizing portion can employ any suitable and suitable polarizing member. The polarizer is represented by a resin film. The resin film is a film of a polyvinyl alcohol-based resin (hereinafter referred to as "PVA-based resin") containing a dichroic substance. The polarizing member may be a single film or a resin layer (represented as a PVA-based resin layer) formed on the resin substrate. The laminate of the resin substrate and the resin layer can be obtained, for example, by a method of forming a material containing the above resin film. A method in which a coating liquid is applied to a resin substrate, a method of laminating a resin film on a resin substrate, and the like.

The above dichroic substance may, for example, be iodine or an organic dye. These may be used alone or in combination of two or more. Ideally, iodine is used. When the non-polarized portion is formed by using the adhesive film of the present invention and decolorized by chemical treatment, the iodine complex contained in the resin film (polarizer) is appropriately reduced, so that a non-polarized portion having appropriate characteristics can be formed.

Any suitable resin can be used for the PVA-based resin. For example, polyvinyl alcohol, ethylene-vinyl alcohol copolymer. Polyvinyl alcohol can be obtained by saponifying polyvinyl acetate. The ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene-vinyl acetate copolymer. The degree of saponification of the PVA-based resin is usually from 85 mol% to 100 mol%, preferably from 95.0 mol% to 99.95 mol%, more preferably from 99.0 mol% to 99.93 mol%. The degree of saponification can be calculated in accordance with JIS K 6726-1994. By using such a saponification degree PVA-based resin, a polarizing member excellent in durability can be obtained. When the degree of saponification is too high, there is a gelatinization.

The average degree of polymerization of the PVA-based resin can be appropriately selected depending on the purpose. The average degree of polymerization is usually from 1000 to 10,000, preferably from 1200 to 4500, and more preferably from 1,500 to 4,300. However, the average degree of polymerization can be calculated in accordance with JIS K 6726-1994.

The polarizer is desirably exhibiting absorption dichroism at any of wavelengths of 380 nm to 780 nm. The single-transmittance (Ts) of the polarizer (excluding the non-polarizing portion) is preferably 39% or more, more preferably 39.5% or more, still more preferably 40% or more, and particularly preferably 40.5% or more. However, the theoretical upper limit of the monomer transmittance is 50%, and the practical upper limit is 46%. Also, the single transmittance (Ts) is by JIS The Y value of the Z8701 2D field of view (C light source) measured and corrected for the visual sensitivity is measured by, for example, a microscopic spectroscopic system (manufactured by Lambda Vision Inc., LVmicro). The degree of polarization of the polarizer is preferably 99.9% or more, more preferably 99.93% or more, and still more desirably 99.95% or more.

The thickness of the polarizer can be set to an arbitrary and suitable value. The thickness is preferably 30 μm or less, more preferably 25 μm or less, still more desirably 20 μm or less, and particularly preferably less than 10 μm. On the other hand, the thickness is preferably 0.5 μm or more, and more preferably 1 μm or more. If it is such a thickness, a polarizing member having excellent durability and optical characteristics can be obtained. The thinner the thickness, the better the non-polarized portion can be formed. For example, when the non-polarizing portion is formed by decolorization by chemical treatment, the contact time between the treatment liquid and the resin film (polarizer) can be shortened.

The absorption axis of the polarizer can be set in any suitable direction in accordance with the purpose. The direction of the absorption axis may be, for example, a strip direction or a width direction. The polarizer having an absorption axis in the longitudinal direction has an advantage of being excellent in manufacturing efficiency. The polarizer having the absorption axis in the width direction has an advantage that, for example, a phase difference film having a slow axis in the longitudinal direction is laminated with a so-called roll-to-roll.

The polarizer can be fabricated by any suitable method. When the polarizing member is a single PVA-based resin film, the polarizing member can be obtained by a method well known in the art well known in the art. When the polarizer is a PVA-based resin layer formed on a resin substrate, the polarizer can be obtained, for example, by the method described in JP-A-2012-73580. In this specification, the entire disclosure of this publication is incorporated herein by reference.

The polarizer can be formed in an optional and suitable form in a non-polarizing portion to be described later. Specifically, the polarizer provided in the non-polarized portion may be The single PVA-based resin film may be a laminate of a resin substrate/PVA-based resin layer, or a laminate in which a protective film is disposed on one side or both sides of a PVA-based resin film or a PVA-based resin layer (ie, a polarizing plate) ). The polarizing plate provided in the non-polarizing portion may have an adhesive layer in order to be attached to the image display device. Moreover, the polarizing plate can have an arbitrary and suitable optical functional layer for the purpose. Representative examples of the optical functional layer include a phase difference film (optical compensation film) and a surface treatment layer. Hereinafter, a case where a non-polarizing portion is formed for a polarizer having a polarizing plate having a polarizer/protective layer as a polarizing plate will be described.

C-2. Formation of non-polarized parts

As shown in FIG. 4, the adhesive film 100 is bonded to the surface of the polarizing plate 200 on the side of the polarizer by a roll-to-roller. The adhesive film 100 is an adhesive film of the present invention as described in the above item A. In the illustrated example, the arrangement pattern of the through holes of the adhesive film corresponds to the arrangement pattern of FIGS. 1 and 3A. In the present specification, the "roller-to-roller" means that the roll-like film is conveyed while the long direction of each other is aligned. In the representative, the adhesive film is peelably attached to the polarizing member. By using the adhesive film of the present invention, the non-polarizing portion can be formed by the decoloring treatment immersed in the decolorizing liquid, so that the polarizing member having the non-polarizing portion can be obtained with a very high manufacturing efficiency. Further, since the adhesive film of the present invention can be used as a surface protective film for a polarizing plate in a decoloring treatment, the adhesive film of the present invention is sometimes referred to as a first surface protective film. Here, the surface protective film is a film which temporarily protects the polarizing plate during work and can be peeled off at an arbitrary and suitable time point, unlike a polarizer protective film which is simply called a protective film.

When the polarizer is laminated with the adhesive film by the roll-to-roller, it can be long The strip-shaped adhesive film is taken up into a roll of adhesive film roll to roll out the adhesive film, which can be laminated on the polarizing member, or can be continuously laminated (not temporarily taken up by the adhesive film) after the adhesive film is formed into the through hole. .

On the other hand, the surface protective film (second surface protective film) is bonded to the surface of the protective film side of the polarizing plate by a roll-to-roller (not shown). The second surface protective film is detachably attached to the polarizer protective film by an optional and suitable adhesive. By using the second surface protective film, the polarizing plate (polarizer/protective film) can be appropriately protected in the decoloring treatment by immersion. In addition to the through hole, the second surface protection film may be the same film as the adhesive film (first surface protection film) of the present invention. Further, as the second surface protective film, a film which is soft like a polyolefin (for example, polyethylene) film (for example, a low modulus of elasticity) can also be used. The second surface protection film may be bonded to the first surface protection film at the same time, or may be bonded before the first surface protection film is bonded, or may be bonded after bonding the first surface protection film. It is desirable to bond the second surface protection film before bonding the first surface protection film. For this procedure, there is the advantage of preventing damage to the protective film and preventing the through-holes of the adhesive film from being transferred to the protective film when the film is taken up. The aspect in which the second surface protective film is bonded before bonding the first surface protective film is suitably applied, for example, to a case where the polarizing material is a PVA-based resin layer formed on a resin substrate. Specifically, the laminate of the polarizer protective film and the second surface protective film may be formed, and the laminate may be bonded to the laminate of the resin substrate and the polarizer, and then the resin substrate may be peeled off, and then the first surface protective film may be peeled off. Bonded to the peeling surface.

Next, as shown in FIG. 5, the laminated film of the present invention (first surface protective film) / polarizer / protective film / second surface protective film Provided in chemical bleaching treatment. The chemical bleaching treatment is representative of contacting the laminate with a decolorizing liquid (e.g., an alkaline solution). The chemical decolorization treatment may further include removing the alkaline solution, contacting the laminate with the acidic solution, and removing the acidic solution. The details will be described below.

The contact of the laminate with the alkaline solution can be carried out by any suitable means. As a representative example, for example, the laminate is immersed in an alkaline solution or an alkaline solution is applied or sprayed to the laminate. It is preferred to impregnate. As shown in Fig. 5, since the decoloring treatment can be performed while conveying the laminated body, the manufacturing efficiency is remarkably high. As described above, the impregnation can be achieved by using the first surface protective film (and the second surface protective film as required). Specifically, by immersing in an alkaline solution, only a portion of the polarizer corresponding to the through hole of the adhesive film (first surface protective film) of the present invention can be brought into contact with the alkaline solution. For example, when the polarizer contains iodine as a dichroic substance, by bringing the polarizer into contact with the alkaline solution, the iodine concentration of the contact portion of the polarizer with the alkaline solution can be reduced, and as a result, the contact portion can be selectively selected only. (The non-polarizing portion can be formed by the through hole of the adhesive film of the present invention). As described above, according to the present embodiment, the non-polarizing portion can be selectively formed in a predetermined portion of the polarizing member with a very high manufacturing efficiency without complicated operations. On the other hand, in the case where iodine remains in the polarizer, even if the iodine complex is destroyed to form the non-polarized portion, the iodine complex is formed again with the use of the polarizer, and the non-polarized portion has no desired characteristics. . In the present embodiment, iodine itself can be removed from the polarizer (substantially non-polarized portion) by the removal of the alkaline solution described later. As a result, it is possible to prevent the characteristic change of the non-polarized portion accompanying the use of the polarizer.

The formation of the non-polarizing portion using the alkaline solution will be described in further detail. After contact with a predetermined portion of the polarizer, the alkaline solution penetrates into the interior of the predetermined portion. The iodine complex contained in the predetermined portion is reduced to become an iodide ion by the alkali contained in the alkaline solution. By reducing the iodine complex to iodide ions, the polarization properties of this portion will substantially disappear and a non-polarized portion will be formed in this portion. Moreover, the transmittance of the portion can be improved by reduction of the iodine complex. The iodine that becomes iodide ions moves from this part to the solvent of the alkaline solution. Thus, iodide ions can be removed from the portion together with the alkaline solution by the alkaline solution removal described later. In this way, the non-polarizing portion can be selectively formed in a predetermined portion of the polarizing member, and the non-polarizing portion does not change with time and is relatively stable. Further, by adjusting the material, the thickness and the mechanical properties of the adhesive film (more specifically, the resin film and the adhesive layer) of the present invention, the concentration of the alkaline solution, and the immersion time of the laminate for the alkaline solution, etc., it is possible to prevent The alkaline solution penetrates into an undesired portion (resulting in forming a non-polarized portion at an undesired portion).

Any suitable basic compound can be used as the basic compound contained in the above alkaline solution. Examples of the basic compound include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; hydroxides of alkaline earth metals such as calcium hydroxide; inorganic alkali metal salts such as sodium carbonate; and organic bases such as sodium acetate. Metal salt, ammonia water, etc. The basic compound contained in the alkaline solution is preferably an alkali metal hydroxide, more preferably sodium hydroxide, potassium hydroxide or lithium hydroxide. By using an alkaline solution containing an alkali metal hydroxide, the iodine complex can be ionized with good efficiency, and the non-polarized portion can be formed relatively easily. These basic compounds may be used singly or in combination of two or more. use.

Any suitable solvent may be used as the solvent of the above alkaline solution. Specific examples thereof include alcohols such as water, ethanol, and methanol, ethers, benzene, chloroform, and a mixed solvent thereof. From the viewpoint of allowing the iodide ion to migrate well to the solvent and easily removing the iodide ion in the alkaline solution removal described later, the solvent is preferably water or alcohol.

The concentration of the above alkaline solution is, for example, 0.01 N to 5 N, preferably 0.05 N to 3 N, more preferably 0.1 N to 2.5 N. When the concentration of the alkaline solution is within this range, the iodine concentration inside the polarizer can be effectively reduced, and ionization of the iodine complex other than the predetermined portion can be prevented.

The liquid temperature of the above alkaline solution is, for example, 20 ° C to 50 ° C. The contact time of the laminate (substantially a predetermined portion of the polarizer) with the alkaline solution may be set according to the thickness of the polarizer, the type of the basic compound contained in the alkaline solution used, and the concentration of the basic compound, for example, 5 Seconds ~ 30 minutes.

After the alkaline solution is brought into contact with a predetermined portion of the polarizer, it can be removed by any suitable means according to the demand. Specific examples of the method for removing the alkaline solution include washing, wiping removal by suction, suction removal, natural drying, heat drying, air drying, and vacuum drying. It is preferred to wash, because the removal performance of the alkaline solution is good, no complicated device is required, and the manufacturing efficiency is good. The solution to be used for washing may be, for example, water (pure water), an alcohol such as methanol or ethanol, an acidic aqueous solution, or a mixed solvent thereof. Ideal for water. The cleaning representative can be paralleled while transporting the laminated body as shown in FIG. 5. Washing can also be done several times. The drying temperature at the time of removing the alkaline solution by drying is, for example, 20 ° C to 100 ° C.

The laminate which has been in contact with the alkaline solution (substantially a predetermined portion of the polarizer) may be further contacted with the acidic solution, depending on the demand. The contact of the laminate with the acidic solution can be carried out by any suitable means. In the case of contact with an alkaline solution, it is preferred to use impregnation. The alkaline solution remaining in the non-polarizing portion can be removed to a better extent by contact with an acidic solution. Moreover, by contact with an acidic solution, the dimensional stability and durability of the non-polarized portion can be improved. The contact with the acidic solution may be carried out after the removal of the alkaline solution, or may be carried out without removing the alkaline solution.

Any suitable acidic compound can be used as the acidic compound contained in the above acidic solution. Examples of the acidic compound include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, hydrogen fluoride, and boric acid; and organic acids such as formic acid, oxalic acid, citric acid, acetic acid, and benzoic acid. The acidic compound contained in the acidic solution is preferably a mineral acid, more preferably hydrochloric acid, sulfuric acid or nitric acid. These acidic compounds may be used singly or in combination.

As the solvent of the above acidic solution, those exemplified as the solvent of the above alkaline solution can be used. The concentration of the above acidic solution is, for example, 0.01 N to 5 N, preferably 0.05 N to 3 N, more preferably 0.1 N to 2.5 N.

The liquid temperature of the above acidic solution is, for example, 20 ° C to 50 ° C. The contact time of the laminate (substantially a predetermined portion of the polarizer) with the acidic solution may be set according to the thickness of the resin film (polarizer) or the type of the acidic compound contained in the acidic solution used and the concentration of the acidic compound, for example, 5 seconds. Clock ~ 30 minutes. According to the demand, the laminate may be removed by wiping or the like immediately after contact with the acidic solution.

The above acidic solution may be in contact with a predetermined portion of the polarizer It is removed by any suitable means according to the demand. It is preferable to wash as in the case of removing the alkaline solution. Examples of the solution to be used for washing include water (pure water), an alcohol such as methanol or ethanol, an acidic aqueous solution, and a mixed solvent thereof. Ideal for water. The cleaning representative can be paralleled while transporting the laminated body as shown in FIG. 5. Washing can also be done several times.

In the present embodiment, when the acidic solution is removed by washing, the layered body after the removal of the acidic solution can be supplied to the cleaning solution for removal and drying (not shown). The removal of the cleaning liquid (represented as water) can be carried out by any suitable means. Specific examples include a gas blow by a blower, a layered body passing through a sponge roll, and the like. By the removal of the cleaning liquid, the cleaning liquid remaining in the through-hole portion of the first surface protective film can be removed to a better extent, so that the adverse effect of the residual cleaning liquid on the polarizer can be prevented. Drying can be carried out, for example, by conveying the laminate in an oven. The drying temperature is, for example, 20 ° C to 100 ° C, and the drying time is, for example, 5 seconds to 600 seconds.

As a representative, the adhesive film (first surface protective film) of the present invention and the second surface protective film can be peeled off after the non-polarized portion is formed as described above.

By setting the arrangement pattern of the through holes of the adhesive film of the present invention as described above, the non-polarized portion can be formed in a predetermined arrangement pattern at a predetermined position of the elongated polarizer. A polarizer having a non-polarizing portion can be used, for example, for an image display device having a camera portion.

In the representative, when the polarizer is mounted on a predetermined size image display device and cut into a predetermined size, the non-polarized portion is disposed at a position corresponding to the camera portion of the image display device. Therefore, want to only grow from one When the strip-shaped polarizer cuts a polarizer of one size, the non-polarized portion can be disposed at substantially equal intervals in both the strip direction and the width direction as shown in FIG. If it is configured for this purpose, the size of the image-cutting device can be easily matched to control the predetermined size of the cutting polarizer, thereby improving the yield. Further, since the position of the non-polarizing portion can be correctly set, the position of the non-polarizing portion in the obtained polarizing member of a predetermined size can also be favorably controlled. As a result, since the difference in the position of the non-polarizing portion of the polarizing member of each predetermined size obtained becomes small, a polarizing member of a predetermined size having no quality variation can be obtained. When a plurality of sizes of polarizers are to be cut from a long strip of polarizer, the interval between the non-polarized portions in the strip direction and/or the width direction may be changed according to the size of the polarizer to be cut. As described above, by appropriately setting the arrangement pattern of the through holes of the adhesive film of the present invention, the non-polarized portion can be formed in a desired arrangement pattern.

The transmittance of the non-polarizing portion (for example, the transmittance measured by light having a wavelength of 550 nm at 23 ° C) is preferably 50% or more, more preferably 60% or more, still more preferably 75% or more, and particularly preferably 90%. the above. With such a transmittance, the desired transparency as a non-polarizing portion can be ensured. As a result, when the polarizer is disposed such that the non-polarized portion corresponds to the camera portion of the image display device, it is possible to prevent adverse effects on the camera imaging performance.

The content of the dichroic material in the non-polarized portion is preferably 1.0% by weight or less, more preferably 0.5% by weight or less, still more preferably 0.2% by weight or less. When the content of the dichroic substance in the non-polarized portion is within this range, the above transmittance can be sufficiently satisfied.

The shape of the non-polarized portion can be used without any adverse effect on the camera performance of the image display device using the polarizer. Desirable shape. By appropriately setting the shape of the through hole of the adhesive film of the present invention, a non-polarized portion having a desired plan view shape can be formed.

Thus, an example of selective treatment of a predetermined portion of an elongated film using the adhesive film of the present invention is described for the formation of a non-polarized portion of the elongated polarizer, but those skilled in the art are aware of the adhesive of the present invention. The film may be applied in a similar procedure to the other selective treatments described above.

Example

[Example 1]

A long laminated body (width: 1200 mm, length: 43 m) having an ester film (thickness 38 μm )/adhesive layer (thickness 5 μm )/spacer (thickness 25 μm ) was prepared. A carrier film having an ester-based film (thickness: 38 μm )/adhesive layer (thickness: 5 μm ) was bonded to the surface of the ester-based film of the laminate by a roll-to-roll (width: 1200 mm, length: 43 m) A laminate having a carrier film is produced.

Next, the layered body with the carrier film was cut into a cutting edge having a depth of 80 μm from the separator surface by using a punching device, and was half-cut into a circular shape having a diameter of 2.4 mm so as not to penetrate the carrier film. . The cut half is performed every 250 mm in the strip direction and every 400 mm in the width direction.

Next, the carrier film was peeled off from the laminate to obtain an adhesive film.

[Embodiment 2]

Obtained in the same manner as in Example 1 except that a laser cutting machine (CO ₂ laser, wavelength: 9.4 μm , output: 10 W) was used instead of the punching device to perform dicing (cutting depth: 80 μm ). Adhesive film.

The following evaluations are carried out for each embodiment.

Perforated waste

It was confirmed whether or not the cut perforated waste was removed at the time of peeling of the carrier film.

2. Adhesive appearance of the adhesive film

The separator was peeled off, and the adhesive film was attached to a commercially available polarizing member and its appearance was observed with a microscope.

In each of the examples, when the carrier film is peeled off, it is produced by halving The perforated waste was completely removed.

The obtained adhesive film was attached to the polarizing member and the bonding state of the polarizing member and the adhesive film was observed. As a result, as shown in Fig. 6, no air bubbles were mixed between the polarizing member and the adhesive film.

[Production of polarizing plate]

As the substrate, a long strip-shaped amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100 μm ) having a water absorption ratio of 0.75% and a Tg of 75 ° C was used. One side of the substrate was subjected to corona treatment, and the corona treated surface was coated at 25 ° C to contain polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetamidine at a ratio of 9:1. An aqueous solution of a modified PVA (degree of polymerization: 1200, acetylation of 4.6%, saponification degree of 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Co., Ltd., trade name "Gohsefimer Z200"), and dried to form a A PVA-based resin layer having a thickness of 11 μm was used to form a laminate.

The obtained laminate was subjected to a uniaxial extension of the free end in the longitudinal direction (longitudinal direction) between the rolls having a peripheral speed of 120 ° C in an oven at 120 ° C to 2.0 times (assisted extension in air).

Next, the laminate was immersed in an insoluble bath (boric acid aqueous solution prepared by mixing 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 30 ° C for 30 seconds (insolubilization treatment).

Next, the iodine concentration and the immersion time were adjusted while the polarizing plate was set to a predetermined transmittance, and this was immersed in a dye bath having a liquid temperature of 30 °C. In the present embodiment, it was immersed in an aqueous iodine solution prepared by blending 0.2 part by weight of iodine with respect to 100 parts by weight of water and blending 1.5 parts by weight of potassium iodide (dyeing treatment).

Subsequently, the mixture was immersed in a crosslinking bath at a liquid temperature of 30 ° C (a boric acid aqueous solution prepared by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid) with respect to 100 parts by weight of water (crosslinking treatment).

Then, the laminate was immersed in a boric acid aqueous solution (mixing 4 parts by weight of boric acid and 5 parts by weight of potassium iodide mixed with 100 parts by weight of water) at a liquid temperature of 70 ° C while allowing it to be at a peripheral speed. The uniaxial stretching (water extension) is performed between the mutually different roller members so as to have a total extension ratio of 5.5 times in the longitudinal direction (longitudinal direction).

Thereafter, the laminate was immersed in a washing bath at a liquid temperature of 30 ° C (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) (washing treatment).

Next, a PVA-based resin aqueous solution (manufactured by Nippon Synthetic Chemical Co., Ltd., trade name "Gohsefimer (registered trademark) Z-200", resin concentration: 3% by weight) was applied to the surface of the PVA-based resin layer of the laminate and bonded. After the protective film (thickness 25 μm ), it was heated in an oven maintained at 60 ° C for 5 minutes. Then, the substrate was peeled off from the PVA-based resin layer to obtain a polarizing plate (width: 1200 mm, length: 43 m) having a polarizing plate having a transmittance of 42.3% and a thickness of 5 μm .

[Formation of transparent parts]

The spacer was peeled off from the polarizer side of the obtained polarizing plate, and the adhesive film obtained in each of the examples was bonded to the roll-to-roller to obtain a polarizing film laminate.

From the adhesive film of the obtained polarizing film laminate, a room temperature aqueous sodium hydroxide solution (1.0 mol/L (1.0 N)) was dropped on the exposed portion of the polarizing member and left for 60 seconds. Then, the aqueous sodium hydroxide solution dropped was removed with a rag, and then the adhesive film was peeled off to obtain a polarizing plate (polarizer) in which a transparent portion was formed.

The following measurement was performed for the transparent portion formed using the adhesive film of each Example.

1. Transmittance (Ts)

The measurement was carried out using a spectrophotometer (product name "DOT-3" manufactured by Murakami Color Research Institute Co., Ltd.). The transmittance (T) is the Y value of the visual sensitivity correction by the 2 degree field of view (C light source) of JIS Z 8701-1982.

2. Iodine content

The iodine content of the transparent portion of the polarizer was determined by fluorescent X-ray analysis. Specifically, the iodine content of the polarizer was determined from the X-ray intensity measured under the following conditions by using a detection line prepared in advance using a standard sample.

. Analytical device: Ricoh X-ray analyzer (XRF) product name "ZSX100e"

. For the cathode: 铑

. Analytical crystal: lithium fluoride

. Excitation light energy: 40kV-90mA

. Iodine test line: I-LA

. Quantitative method: FP method

. 2θ angle peak: 103.078deg (iodine)

. Measurement time: 40 seconds

In each of the examples, a transparent portion having a transmittance of 93% to 94% and an iodine content of 0.15% by weight or less was formed, and these functions as a non-polarizing portion. Further, the non-polarizing portion and the shape of the through hole of the adhesive film correspond to a circular shape having a diameter of 2.4 mm.

Industrial availability

The adhesive film of the present invention is suitably used as a surface protective film or mask when a predetermined portion of a film (represented as a long film) is to be selectively treated.

Claims (10)

An adhesive film comprising a long resin film, an adhesive layer provided on one surface of the resin film, and a long spacer which is peelably temporarily bonded to the adhesive layer, and has a whole penetrating the resin film, The adhesive layer and the through hole of the spacer are disposed at predetermined intervals along the longitudinal direction and/or the width direction, and the adhesive film is attached to the strip in such a manner as to be aligned with each other in the longitudinal direction The film is used to selectively perform a treatment on a portion of the elongated film corresponding to the through hole. The adhesive film of claim 1, wherein the through holes are disposed at a predetermined interval in the longitudinal direction. The adhesive film of claim 1, wherein the through holes are disposed at substantially equal intervals along at least the longitudinal direction. The adhesive film according to claim 1, wherein the through holes are arranged at substantially equal intervals in the longitudinal direction and the width direction. The adhesive film according to claim 1, wherein a linear direction connecting the adjacent through holes is in a range of ±10° with respect to the longitudinal direction and/or the width direction. The adhesive film of claim 1, wherein the through holes are arranged in a dot shape. The adhesive film of claim 1, wherein the through hole has a shape of a plan view that is slightly rounded or slightly rectangular. The adhesive film of claim 1, which is wound into a roll. The adhesive film according to any one of claims 1 to 8, which can be used for producing a long strip-shaped polarizing member having a non-polarizing portion. The adhesive film according to any one of claims 1 to 8, wherein a peripheral edge of the through-hole on the side of the adhesive layer is formed as a circular arc surface.